Abstract 16778: Effectiveness of Platelet Inhibition on Reducing High-Intensity Transient Signals to Cerebral Circulation During Tavi

Abstract

Introduction: Despite the established dual antiplatelet treatment, embolic cerebrovascular events remain a major concern peri-operatively and following Transcatheter Aortic valve Implantation (TAVI). High Residual Platelet Reactivity (RPR) may contribute to platelet aggregation, propagating thrombosis on implanted materials. Therefore, we evaluated whether high RPR may predispose to an increased number of cerebrovascular emboli during the procedure. Methods: Consecutive patients who underwent transfemoral TAVI with Evolut™ R bioprosthesis were prospectively studied. Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor was administered to all patients 24 hours prior to the procedure at loading dose. The number of detected High Intensity Transient Signals (HITS) was assessed using Rimed Digi-Lite™ Transcranial Doppler on both cerebral arteries during the following phases of the procedure; Phase 0: 30 minutes prior to procedure initiation, Phase I: between access site puncture and introduction of the delivery system, Phase II: during the implantation of the bioprosthesis, until the removal of the delivery system. Platelet inhibition was measured prior to the procedure and expressed in PRU, using the VerifyNow® assay and defined as high RPR if PRU≥208. Results: Out of 28 total patients (81±7 years, 18 males (64%)), 12 patients (81±9 years, 8 males (66.7%)) had PRU ≥208 (high RPR group), while 16 patients (81±5 years, 10 males (62.5%)) had PRU<208 (low RPR group). All device implantations were performed without balloon pre-dilation. Among the high RPR group, a statistically significant higher number of HITS was recorded compared to the low RPR group (707±149 vs. 530±152, p: 0.004). This was mainly driven by the number of HITS detected during Phase II, compared to the rest procedure stages (247±84 vs. 165±28, p:0.004). A statistical significant correlation of PRU with the total number of HITS was found (r2: 0.25, p: 0.006). Conclusions: High RPR after dual antiplatelet loading resulted in larger burden of embolic HITS during TAVI. This may has implications for future strategies for cerebral embolic protection.